Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: tireshredder on May 26, 2009, 10:12:44 PM

Title: 2 sensors to 1
Post by: tireshredder on May 26, 2009, 10:12:44 PM
Ok, I'm looking into using a truck computer for my engine swap, so I don't have to get a chip, and one of the problems I see is that the truck only uses one O2 sensor.  I just put in dual exhaust, so I can't put the sensor on the Y pipe.  I was thinking of only running one side.  I have to block off the passenger side anyway.  I'm wondering if this would effect it much.  The sensors ain't used for meter fuel anymore, right?

There are 4 pins for the O2 sensors: 2 sensor wires and 2 grounds.  I could ground the ground wire to the chassis, and repin the other one to the right place.
Title: 2 sensors to 1
Post by: ipsd on May 26, 2009, 11:17:21 PM
Quote from: tireshredder;274517
Ok,
There are 4 pins for the O2 sensors: 2 sensor wires and 2 grounds.  I could ground the ground wire to the chassis, and repin the other one to the right place.


Yup 4 wires but it goes like this. 2grounds, one for heater, one for sensor.

Stuckman
Title: 2 sensors to 1
Post by: tireshredder on May 26, 2009, 11:59:14 PM
What heater? It can't be the "make me warm and toasty" heater.

I was referring to pins 44, 49, 43, and 29.
http://fordfuelinjection.com/5.0Lpinouts.html
Title: 2 sensors to 1
Post by: ipsd on May 27, 2009, 01:45:17 AM
There is a Heater inside the O2 sensor. It is in there to make the Sensor Warm and Toasty quicker so it gets to temp and gives a better reading to the computer. So from the row I'm reading at that link there is a heated O2 sensor in each bank left and right. HEGO is the heater part of the O2 sensor. You have power to it and Ground from it. Both left and right sides.

Stuckman
Title: 2 sensors to 1
Post by: Lightningbird on May 27, 2009, 02:29:42 AM
The faster an O2 sensor comes up to operating temp the more accurate it is. The heated O2 sensor is what you are dealing with and it is essentually a "light bulb" +12 volts one side, - Ground on the other. Then sensor wire and ground on the other side.
Title: 2 sensors to 1
Post by: tireshredder on May 27, 2009, 02:50:59 PM
Quote from: ipsd;274543
So from the row I'm reading at that link there is a heated O2 sensor in each bank left and right. HEGO is the heater part of the O2 sensor. You have power to it and Ground from it. Both left and right sides.

Stuckman



If those pins just send power to the heaters in the sensors (if I'm reading your post right), then where does the signal come in from them to tell the computer the ratio?
Title: 2 sensors to 1
Post by: ipsd on May 27, 2009, 04:12:06 PM
each sensor has like 4 wires. 2 wires for the heater then 2 wires for the sensor part. What you are missing is in that diagram they show both a Left O2 sensor and a Right O2 sensor. So that would have 8 wires in all. Four wires for heaters in O2 sensor and 4 wires for the sensor part.

Stuckman
Title: 2 sensors to 1
Post by: softtouch on May 27, 2009, 05:15:08 PM
87 EVTM:
The ground on the bottom of the sensor from being screwed into the exhaust manifold.
The ground wires from the EEC go the back of the heads.
Title: 2 sensors to 1
Post by: SLEEPER T-BIRD 87 on May 27, 2009, 07:58:31 PM
I ran a crossover pipe  (h pipe) and used the single sensor.


(truck/van harness in my maverick BTW)
Title: 2 sensors to 1
Post by: tireshredder on May 28, 2009, 12:30:14 AM
I was thinking that, cause I do have the H pipe, but we weren't sure how well that would work due to flow.  But I guess that works well enough.
Title: 2 sensors to 1
Post by: Sick88Tbird on May 28, 2009, 05:45:06 PM
I'm swapping a 351 into my 'Bird this weekend...I plan on using an HO computer...with a Crane Cams Lightning-spec flat-tappet cam, ported GT40 irons and a pretty restrictive intake set up...if everything is done proportionally(and that's the hard part), it should run fine...I may have to stay tuned to this thread to see your progress.

What year is your 351 out of? 

Good luck,
Don
Title: 2 sensors to 1
Post by: tireshredder on May 28, 2009, 08:31:30 PM
It was an 88 truck motor.  I just did the basic rebuild.  When I started this, I knew jack squat, and it shows.  But I figure I'll do better next time around, and this isn't going to be too bad.
Title: 2 sensors to 1
Post by: Sick88Tbird on May 28, 2009, 10:04:59 PM
The truck 5.8's were lower compression (around 8.8:1) and had pretty mild cams...if you're using a stock cam, it should make peak power around 3800rpm.  Swapping in a stock 5.8 truck engine is like doing an HO swap + a little more torque, for a whole lot more work.  I tried to leave myself the opportunity for more power in the future with intake upgrades, as I've had the heads milled down to 59cc to bump the compression and I took the time to port them also.

I'm a big advocate of speed density, don't ask me why because I honestly don't know...lol....maybe because everybody goes straight to mass air and I know guys running plenty fast with SD.

Good luck and keep us posted!
-Don